Clinical application prospects of gastric pacing for treating postoperative gastric motility disorders

Similar to the heartbeat, gastric peristalsis is regulated by an electrical rhythm generated by a pacemaker. Thus, electrical dysrhythmia of gastric slow waves will inevitably affect gastric peristalsis and emptying. The recurrence of postoperative gastroparesis is thereby closely related to the abnormalities of electrical dysrhythmia and ectopic pacemakers, resulting in postoperatively persistent gastric motility disorders in some severe cases, despite the use of prokinetic and antiemetic drugs. Recent studies have demonstrated that gastric pacing, analogous to pacing the human heart, is an attractive and promising therapy that is both feasible and safe. Gastric pacing has been shown to be strikingly effective in normalizing gastric dysrhythmia, increasing the activity of the gastric slow wave and thereby prompting gastric dynamia and emptying. Furthermore, the long-term utilization of gastric pacing can (i) relieve patients from clinical symptoms, such as nausea and vomiting; (ii) release patients with severe postoperative gastroparesis from relying on prokinetic drugs and the jejunal feeding tube; (iii) return patients to normal oral nutritional intake and provide a more satisfactory nutritional status and most importantly; and (iv) give patients a better quality of life. Overall, research focused on gastric pacing has demonstrated excellent prospects for clinical application in the treatment of postoperative gastroparesis disorders, especially for those unresponsive to prokinetic drugs.     

Abnormal gastric myoelectrical activity and delayed gastric emptying in patients with symptoms suggestive of gastroparesis

Gastric myoelectrical activity modulates gastric motor activity. Abnormalities in gastric myoelectrical activity may be associated with gastric motility disorders. The aim of this study was to investigate the correlation of gastric myoelectrical activity with gastric emptying in symptomatic patients with and without gastroparesis. Ninety-seven patients with symptoms suggestive of gastroparesis participated in the study. Gastric myoelectrical activity was recorded using surface electrogastrography. The electrogastrogram (EGG) was recorded for 30 min in the fasting state and for 120 min after a solid test meal. Gastric emptying of the solid meal was simultaneously monitored for 120 min. Patients with delayed gastric emptying showed a significantly lower percentage of normal gastric slow waves (P<0.03) and a significantly reduced increase of the dominant power in the postprandial EGG (P<0.02). Postprandial EGG parameters were found to be able to predict delayed emptying of the stomach. Postprandial gastric dysrhythmia predicts delayed gastric emptying with an accuracy of 78%, while the abnormality in postprandial EGG power predicts delayed gastric emptying with an accuracy of 75%. All patients with abnormalities in both the rhythmicity and the power had delayed gastric emptying. Patients with delayed gastric emptying have a lower percentage of normal gastric slow waves in the EGG and a lower postprandial increase in the dominant power. Abnormalities in the postprandial EGG seem to be able to predict delayed emptying of the stomach. However, a normal EGG does not seem to guarantee normal emptying of the stomach.     

Electrogastrography in patients with gastroparesis and effect of long-term cisapride

Abnormalities in the gastric pacemaker potentials occur in patients with impaired gastric emptying. It is unclear if treatment effects the underlying rhythm or if normalization of dysrhythmias is important. We examined the effect of cisapride using surface electrogastrograms and radionuclide gastric emptying studies of patients with idiopathic and diabetic gastroparesis. Twelve of 14 patients had abnormal baseline electrogastrograms. After six months of cisapride, four patients had normalization of their electrical activity and six had improvement. Patients with idiopathic gastroparesis had an increase in gastric emptying at 120 min from 48.9±3.8% (baseline) to 70.9±6.0% (six months), P =0.009. Patients with diabetes mellitus had a similar improvement. Patients who had normalization of the electrogastrogram had a greater gastric emptying rate than patients with continued dysrhythmias. Thus, dysrhythmias are important in the etiology for gastroparesis, but other factors need to be examined.This work was in part supported by the Measey Foundation, by NIH grant R01-DK389641-01 A1, and by the Janssen Research Foundation.     

Evaluation of gastric emptying and motility in diabetic gastroparesis with magnetic resonance imaging: effects of cisapride

OBJECTIVE: The motor mechanisms that underlie both slow gastric emptying in diabetic gastroparesis and its acceleration by cisapride are poorly understood. We have recently shown that magnetic resonance imaging (MRI) allows concurrent evaluation of both gastric emptying and regional gastric motility. METHODS: Emptying and motility were measured in eight diabetic patients with previously demonstrated delayed gastric emptying using a rapid MRI technique during oral administration of cisapride and placebo. Studies were performed in a double blind fashion and each patient acted as his own control. Subjects were studied supine for 120 min in a 1.5 Tesla MRI scanner after ingestion of 500 ml of 10% Intralipid. Gastric emptying corrected for the volume of secretions was determined every 15 min using transaxial scans. Each transaxial scan was followed by 120 coronal scans at 1 s intervals. Coronal scans were angled to provide simultaneous imaging of the proximal and distal stomach. MRI studies were also performed in seven diabetic patients with normal emptying who served as disease controls. RESULTS: Emptying was slower in the gastroparetic patients (t(1/2): 124 +/- 10 min) compared to patients with normal emptying (81 +/- 9 min, p < 0.05). Cisapride accelerated gastric emptying (74 +/- 5 vs 124 +/- 10 min) in patients with gastroparesis. The contraction amplitudes in the proximal stomach of gastroparetic patients were increased during cisapride treatment (17.2% +/- 1.8% vs 13.2% +/- 0.6%; p < 0.02), whereas antral contraction frequency, amplitude, and velocity were unchanged. CONCLUSIONS: We conclude that cisapride-induced acceleration of liquid gastric emptying in diabetic gastroparesis does not appear to result from changes in antral contractility, but may be related to changes in proximal gastric tone or gastric outlet resistance.     

Gastric electric stimulation for the treatment of gastroparesis

Gastric electric stimulation is an emerging therapy for refractory gastroparesis. Several methods have been used to electrically stimulate the stomach. Initial studies used gastric electrical pacing, which entrains and paces the gastric slow waves at a slightly higher rate than the patient’s normal myoelectric frequency of 3 cycles per minute (cpm). The technique currently practiced uses high-frequency, low-energy stimulation at four times the basal rate (12 cpm). Results from published studies with high-frequency stimulation reveal an improvement in symptoms, primarily of nausea and vomiting, and primarily in patients with diabetic gastroparesis, with only a modest change in gastric emptying. As treatment with gastric electric stimulation evolves, further delineation of its overall effectiveness, the type of patient that will likely respond, optimal electrode placement(s), and stimulus parameters should be explored.     

Treatment of gastroparesis with electrical stimulation

Electrically stimulating the stomach to treat gastroparesis has been proposed by investigators for decades. With the development of techniques of implantable pacing devices and electrodes and promising preliminary results in chronic pacing studies, gastric electrical stimulation (GES) has received increasing attention recently among researchers and clinicians. A number of studies have been performed to investigate the effects of GES on gastric motility, gastric emptying, and gastrointestinal symptoms in both dogs and humans. Based on the frequency of the electrical stimulus used for chronic treatment of gastroparesis, gastric electrical stimulation can be classified into low-frequency stimulation (LFS) and high-frequency stimulation (HFS). Although some of the results are still controversial, the majority of these studies seem to indicate that LFS is able to normalize gastric dysrhythmias and entrain gastric slow waves and accelerate gastric emptying. On the other hand, HFS has no effect on gastric emptying but is able to significantly reduce symptoms of nausea and vomiting in gastroparetic patients. GES has provided an exciting new advance in the treatment of gastroparesis and management of upper gastrointestinal symptoms. This paper will review the available studies of GES in the treatment of gastroparesis and current status of this field.     

胃起搏对胃动力紊乱犬胃肌电活动和血浆胃动素水平的影响

背景:胃起搏治疗胃动力紊乱性疾病已引起人们的关注,但其作用机制尚不清楚。目的:研究胃起搏对胃动力紊乱犬胃肌电活动和血浆胃动素水平的影响,观察胃起搏治疗前后胃电参数与血浆胃动素含量的相关性,进而探索胃起搏的作用机制。方法:采用双侧迷走神经干切断术联合应用胰高血搪素建立胃动力紊乱或节律紊乱犬模型。采用4导联胃肠电系统微机分析仪记录胃浆膜肌电活动:采用放射免疫法测定血浆胃动素含量。采用适宜的起搏参数从腹部体表驱动胃电慢波,1次d,每次45min,疗程为30天,均在餐后进行。结果:双侧逃走神经干切断术后,模型犬的餐后胃电主频(4.85 cpm±0.40 cpm)、平均幅度(2.32 mV±0.35 mV)和慢波传播速度(4.06 cm/s±0.40cm/s)均较止常对照犬显著降低(5.37 cpm±0.36 cpm,4.25 mV±0.12 mV.6.92 cm/s±0.24 cm/s,P<0.03),其术后血浆胃动素含量(242.09 pg/ml±17.22 pg/m1)显著高于术前(184.29 pg/ml±9.81 pg ml,P<0.01),且胃电主频、平均幅度和慢波传播速度与胃动素含量呈负相关(P<0.04)。经胃起搏治疗后,模型犬的餐后胃电主频(5.49cpm±0.31 cpm)、平均幅度(3.97mV±0.19mV)和慢波传播速度(5.57 cm/s±0.48 cm/s)均显著高于治疗前(P<0.05),血浆胃动素含量(212.55 pg/ml±11.20 pg/ml)则显著降低(P<0     

Ghrelin enhances gastric emptying in diabetic gastroparesis: a double blind, placebo controlled, crossover study

BACKGROUND: Diabetic gastroparesis is a disabling condition with no consistently effective treatment. In animals, ghrelin increases gastric emptying and reverses postoperative ileus. We present the results of a double blind, placebo controlled, crossover study of ghrelin in gastric emptying in patients with diabetic gastroparesis. METHODS: Ten insulin requiring diabetic patients (five men, six type I) referred with symptoms indicative of gastroparesis received a two hour infusion of either ghrelin (5 pmol/kg/min) or saline on two occasions. Blood glucose was controlled by euglycaemic clamp. Gastric emptying rate (GER) was calculated by real time ultrasound following a test meal. Blood was sampled for ghrelin, growth hormone (GH), and pancreatic polypeptide (PP) levels. Cardiovagal neuropathy was assessed using the Mayo Clinic composite autonomic severity score (range 0 (normal)-3). RESULTS: Baseline ghrelin levels were mean 445 (SEM 36) pmol/l. Ghrelin infusion achieved a peak plasma level of 2786 (188) pmol/l at 90 minutes, corresponding to a peak GH of 70.9 (19.8) pmol/l. Ghrelin increased gastric emptying in seven of 10 patients (30 (6)% to 43 (5)%; p = 0.04). Impaired cardiovagal tone correlated inversely with peak postprandial PP values (p < 0.05) but did not correlate with GER. CONCLUSIONS: Ghrelin increases gastric emptying in patients with diabetic gastroparesis. This is independent of vagal tone. We propose that analogues of ghrelin may represent a new class of prokinetic agents.     

Electrogastrography: physiological basis and clinical application in diabetic gastropathy

Electrogastrography is the recording and measurement of gastric myoelectrical activity from electrodes placed on the surface of the epigastrium. Normal electrogastrograms (EGGs) reflect 3 cycles per min (cpm) gastric myoelectrical activity produced by specialized pacemaker cells, the interstitial cells of Cajal, located in the muscular wall of the gastric corpus and antrum. Gastric dysrhythmias (tachygastrias and bradygastrias) are disturbances of the normal gastric pacesetter potentials and are associated with symptoms of nausea, epigastric fullness, and bloating and with hyperglycemia and delayed gastric emptying. In diabetic gastropathy, the normal 3-cpm electrical rhythm is replaced with bradygastrias, tachygastrias, and mixed or nonspecific dysrhythmias. Diagnosis of gastric dysrhythmias identifies an objective neuromuscular abnormality in diabetic patients with upper gastrointestinal (GI) symptoms. Correction of gastric dysrhythmias decreases upper GI symptoms and may improve gastric emptying all of which may enhance glucose control. The EGG diagnosis of gastric dysrhythmias provides new insights into gastric neuromuscular abnormalities and guides therapies to improve upper GI symptoms in patients with diabetes mellitus.     

Small doses of the unabsorbable substance polyethylene glycol 3350 accelerate oro-caecal transit, but slow gastric emptying in healthy subjects

BACKGROUND: Polyethylene glycol 3350 increases stool frequency and accelerates colonic transit. Used as a laxative, it proved effective in patients with normal and slow transit. Although free of severe side effects, it may cause nausea and vomiting. The effect of this substance on upper gut transit has not been studied. AIM: To investigate the effect of polyethylene glycol 3350 on gastric emptying and oro-caecal transit in 12 healthy subjects. METHODS: In a randomised controlled study, isosmotic polyethylene glycol 3350 electrolyte balanced solution, in the maximal recommended dose or isosmotic electrolyte solution, was administered after breakfast and lunch on separate days. Gastric half-emptying time and oro-caecal transit time were measured using [13C]-octanoate and lactose-[13C] ureide breath tests. RESULTS: Isosmotic polyethylene glycol 3350 electrolyte solution, as compared to isosmotic electrolyte solution, decreased oro-caecal transit time from 424+/-28 to 314+/-17 min (P = 0.001). Gastric half-emptying time was significantly increased (84+/-6 min versus 127+/-14 min; P = 0.006). CONCLUSION: Polyethylene glycol 3350 accelerate oro-caecal transit in healthy subjects, but also cause an important delay in gastric emptying. The delay in gastric emptying may be of clinical significance in patients who have associated gastroparesis.     

Effects of gastric pacing on gastric emptying and plasma motilin

AIM:To investigate the effects of gastric pacing on gastric emptying and plasma motilin level in a canine model of gastric motility disorders and the correlation between gastric emptying and plasma motilin level.METHODS: Ten healthy Mongrel dogs were divided into:experimental group of six dogs and control group of four dogs. A model of gastric motility disorders was established in the experimental group undergone truncal vagotomy combined with injection of glucagon. Gastric half-emptying time (GEt1/2) was monitored with single photon emission computerized tornography (SPECT), and the half-solid test meal was labeled with an isotope-^99mTc sulfur colloid. Plasma motilin concentration was measured with radioimmunoassay (RIA) kit. Surface gastric pacing at 1.1-1.2 times the intrinsic slow-wave frequency and a superimposed series of high frequency pulses (10-30Hz) was performed for 45min daily for a month in conscious dogs.RESULTS:After surgery, GEt1/2 in dogs undergone truncal vagotorny was increased significantly from 56.35&#177;2.99min to 79.42&#177;1.91min (P&lt;0.001), but surface gastric pacing markedly accelerated gastric emptying and significantly decreased GEt1/2 to 64.94&#177;1.75min (P&lt;0.001) in animals undergone vagotomy. There was a significant increase of plasma level of motilin at the phase of IMCⅢ (interdigestive myoelectrical complex, IMCⅢ) in the dogs undergone bilateral truncal vagotomy (baseline vsvagotomy, 184.29&#177;9.81pg/ml vs 242.09&#177;17.22pg/ml;P&lt;0.01).But plasma motilin concentration (212.55&#177;11.20pg/ml; P&lt;0.02) was decreased significantly after a long-term treatment with gastric pacing.Before gastric padng, GEt1/2 and plasma motilin concentration of the dogs undergone vagotomy showed a positive correlation (r=0.867, P&lt;0.01), but after a long-term gastric pacing, GEt1/2 and motilin level showed a negative correlation (r=-0.733, P&lt;0.04).CONCLUSION: Surface gastric pacing with optimal pacing parameters can improve gastric emptying parameters and significantly accelerate gastric emptying and can resume or alter motor function in a canine model of motility disorders. Gastric emptying is correlated well with plasma motilin level before and after padng, which suggests that motilin can modulate the mechanism of gastric pacing byaltering gastric motility.motilin can modulate the mechanism of gastric pacing by altering gastric motility.     

Gastric emptying and subjective symptoms of nausea: lack of effects of a 5-hydroxytryptamine-3 antagonist ondansetron on gastric emptying in patients with gastric stasis syndrome

Thirty-seven consecutive patients referred to a regional gastroenterology outpatient clinic with complaints of persistent nausea had a double isotopic scintigraphic evaluation of solid and liquid gastric emptying. Gastric emptying of both forms followed an exponential model. Marked day to day variation of gastric emptying was noted with a coefficient of variation of approximately 0.20 for both phases. Only 9 of 37 patients had delayed gastric emptying rate of the solid component (greater than 180 min) and no correlation between gastric stasis syndrome and nausea was established. Among these patients the median time for the stomach to empty 50% of the solid component was 261 min and 50% of the liquid component was 66 min. Treatment of these 9 patients shown to have gastric stasis syndrome and further 3 patients with diabetic gastroparesis with ondansetron, a highly selective antagonist of 5-hydroxytryptamine-3-receptors, resulted in a gastric emptying rate which was not statistically faster than after placebo (p = 0.11).     

Gastric Emptying in Patients with Insulin-Requiring Diabetes Mellitus

Gastric emptying of technetium labeled liquid and solid meals were studied in a group of long-standing, insulin-requiring male diabetics to evaluate the relationship of gastroparesis to symptoms, diabetic control, and diabetic complications. Control subjects and three groups of diabetics were studied: A) no neuropathy; B) peripheral neuropathy; and C) peripheral and autonomic neuropathy. Nine diabetics had gastrointestinal symptoms. Gastric t1/2 liquid emptying was similar in all groups and in controls, but liquid gastric emptying in the first 15 min was significantly more rapid in the diabetics than controls. Solid emptying was prolonged in group C patients. There was a significant correlation between t1/2 solid emptying and the severity of neuropathy. The eight patients with slow solid emptying had more neuropathy and gastrointestinal symptoms than the remaining 22 patients. The type and duration of diabetes, diabetic control, and frequency of retinopathy are independent of gastroparesis. These data indicate that delayed emptying of solids is common (27%) in patients with clinically detectable neuropathy and may often be asymptomatic. Visceral autonomic neuropathy seems the most important underlying factor in diabetic gastroparesis.     

Effect of two-channel gastric electrical stimulation with trains of pulses on gastric motility

AIM： To investigate the effect of two-channel gastric electrical stimulation （GES） with trains of pulses on gastric emptying and slow waves.METHODS： Seven dogs implanted with four pairs of electrodes and equipped with a duodenal cannula were involved in this study. Two experiments were performed.The first experiment included a series of sessions in the fasting state with trains of short or long pulses, each lasted 10 min. A 5-min recording without pacing was made between two sessions. The second experiment was performed in three sessions （control, single-channel GES, and two-channel GES）. The stimulus was applied via the 1st pair of electrodes for single-channel GES （GES via one pair of electrodes located at 14 cm above the pylorus）, and simultaneously via the 1st and 3rd channels for two-channel GES （GES via two pairs of electrodes located at 6 and 14 cm above the pylorus）, Gastric liquid emptying was collected every 15 min via the cannula for 90 min.RESULTS： GES with trains of pulses at a pulse width of 4 ms or higher was able to entrain gastric slow waves. Two-channel GES was about 50% more efficient than single-channel GES in entraining gastric slow waves. Two-channel but not single-channel GES with trains of pulses was capable of accelerating gastric emptying in healthy dogs. Compared with the control session, two-channel GES significantly increased gastric emptying of liquids at 15 rain （79.0% ± 6.4% vs 61.3% ± 6.1%, P 〈 0.01）, 30 min （83.2% ± 6.3 % vs 68.2% ± 6.9%, P 〈 0.01）, 60 min （86.9% ± 5.5 % vs 74.1% ± 5.9%, P 〈 0.01）, and 90 rain （91.0% ± 3.4% vs 76.5% ± 5.9%, P 〈 0.01）.CONCLUSION： Two-channel GES with trains of pulses accelerates gastric emptying in healthy dogs and may have a therapeutic potential for the treatment of gastric motility disorders.     

Ischemic gastroparesis: resolution after revascularization

Patients with chronic nausea and vomiting frequently present challenging diagnostic and therapeutic problems. In such patients, gastroparesis of unknown cause, or "idiopathic" gastroparesis, may be the only objective finding. Two middle-aged women with nausea, vomiting, and weight loss of 10 and 26 kg over 6 and 18 months, respectively, were evaluated. Routine laboratory and barium study results were normal. Solid-phase gastric emptying studies showed severe gastroparesis in both patients. Upper endoscopies excluded gastric outlet obstruction. Gastric dysrhythmias (4-cpm and 1-cpm patterns) were recorded using cutaneous electrodes. An abdominal bruit was ascultated in one patient. Abdominal arteriograms in both patients showed total occlusion of all three major mesenteric vessels with collaterals supplied via hemorrhoidal arteries. Bypass grafting procedures of the celiac and superior mesenteric arteries in one patient and of the celiac artery in the other patient were performed. Six months after mesenteric artery revascularization, upper gastrointestinal symptoms had resolved and original weights were regained. Furthermore, normal 3-cpm gastric myoelectrical activity and normal gastric emptying of solids were restored in both patients. In these patients, chronic mesenteric ischemia resulted in a novel and reversible cause of gastroparesis, gastric dysrhythmias, and accompanying symptoms.     

Delayed gastric emptying after distal gastrectomy for gastric cancer

BACKGROUND/AIMS: Gastric surgery may potentiate delayed gastric emptying. The aims of the study were to determine the frequency and causes of delayed gastric emptying in patients who had undergone distal gastrectomy for gastric carcinoma and to assess which factors predispose to its development. METHODOLOGY: 209 patients, who had undergone gastrectomy, were evaluated. RESULTS: Delayed gastric emptying occurred in 4.3% of patients receiving a Billroth-I, and 15.5% of patients receiving a Roux-Y reconstruction (p = 0.01). The patients who had these consecutive symptoms following Roux-Y operation were all clinically diagnosed as having Roux stasis syndrome. The delayed gastric emptying after Roux-Y operation was more frequent in patients receiving extensive lymph node dissection than those receiving conventional dissection (p<0.05). The symptoms spontaneously subsided, and postoperative body weight loss was not significant. CONCLUSIONS: In spite of the strong association between delayed gastric emptying and the Roux-Y procedure, it enables a relatively early return to oral intake.     

Improvement of gastric motility with gastric electrical stimulation in STZ-induced diabetic rats

AIMS: The aims of this study were to observe whether gastric motility was impaired in streptozotocin (STZ)-induced diabetic rats and whether gastric electrical stimulation was able to restore the impaired motility. METHODS: Ten control rats and 30 STZ-induced diabetic rats were used in this study. Gastric slow waves were recorded at baseline and 0, 1, 2, 3 and 4 weeks after the injection of STZ or vehicle. Gastric emptying with (long or short pulses) or without gastric electrical stimulation was measured 6 weeks after STZ injection in a group of 10 diabetic rats each. RESULTS: (1) STZ injection resulted in hyperglycemia and weight loss. (2) Gastric motility was impaired in the diabetic rats. The percentage of normal slow waves was progressively reduced 2 weeks after STZ injection. Compared with the control rats, gastric emptying in the diabetic rats was significantly delayed 6 weeks after STZ injection (60 +/- 3 vs. 79 +/- 2%, p < 0.02). (3) Gastric electrical stimulation with either long or short pulses accelerated gastric emptying in the diabetic rats. (4) Gastric electrical stimulation with long but not short pulses was capable of normalizing gastric dysrhythmia in the diabetic rats. CONCLUSION: Our data show that gastric motility is impaired in STZ-induced diabetic rats as reflected by a progressive reduction in the percentage of normal gastric slow waves and delayed gastric emptying. Moreover, here we show that gastric electrical stimulation normalizes delayed gastric emptying in diabetic rats and this normalization is not attributed to the effect of gastric electrical stimulation on gastric slow waves.     

Inhibitory effects of cholecystokinin on postprandial gastric myoelectrical activity

While a number of studies have investigated the effects of cholecystokinin (CCK) on gastrointestinal motility, little is known on the effects of CCK on gastric myoelectrical activity, which regulates gastric motility. The aim of this study was to investigate the effects of intravenous infusion of CCK-8 on gastric myoelectrical activity in normal humans. Gastric myoelectrical activity was measured in 10 healthy subjects with a noninvasive electrogastrographic technique by placing abdominal electrodes on the epigastric area. Two study sessions were performed in each subject on two separate days with double-blinded infusion of either saline or CCK (24 pmol/kg/hr). The procedure for each session was as follows: (A) 30-min baseline fasting electrogastrogram (EGG); (B) start infusion, another 30-min EGG; (C) give meal, 60-min EGG; and (D) stop infusion, another 60-min EGG. The dominant frequency and peak power (amplitude) of the EGG, and the percentage of normal 2–4 cycles/min slow waves during each recording session were computed and compared between placebo and CCK. It was found that normal 3 cpm slow waves were recorded in all EGGs. Infusion of CCK had no effect on the frequency of the gastric slow wave and did not induce gastric dysrhythmias. It was also found that intravenous infusion of CCK significantly decreased the EGG peak power (amplitude) during the first hour after the meal (the infusion was given during this period) in comparison with placebo (P<0.05). This inhibitory effect on EGG peak power was sustained but not significant during the second postprandial hour (the infusion was not given during this period). It was concluded that intravenous infusion of CCK at a physiological concentration significantly decreased the postprandial EGG amplitude in normal humans, suggesting an inhibitory effect on postprandial gastric motility, but did not change the frequency and regularity of the gastric slow wave.     

Ultrasonographic comparison of gastric motility between diabetic gastroparesis patients with and without metabolic syndrome

Background and Aims:  Diabetic patients with poor glycemic control or long standing disease often have impaired gastric motility. Recently, metabolic factors such as blood glucose have been reported as influencing gastric motility independently of autonomic neuropathy. Many diabetic patients have metabolic syndrome, which is strongly associated with coronary and other diseases. We investigated whether metabolic syndrome influences diabetic gastroparesis patients.
Methods:  We observed gastric motility ultrasonographically in diabetic gastroparesis patients including nine with and nine without metabolic syndrome. Both groups complained of upper abdominal symptoms when hospitalized to improve blood sugar control. All patients underwent upper gastrointestinal endoscopy to rule out gastric and duodenal lesions. All had autonomic neuropathy. Gastric motility was evaluated within 3 days after admission by transabdominal ultrasonography after a test meal.
Results:  Gastric emptying was 45.0 ± 13.7% in patients with and 39.1 ± 11.9% in patients without metabolic syndrome, which was not statistically significant. Frequency of gastric contractions was 8.33 ± 2.78 per 3 min in patients with metabolic syndrome and 7.44 ± 2.13 per 3 min in the others, which was not statistically significant. The motility index, which involves antral contractility, was 3.21 ± 2.18 in patients with metabolic syndrome and 2.80 ± 1.87 in the others, which was not statistically significant.
Conclusions:  Metabolic syndrome did not appear to contribute to delayed gastric motility in diabetic gastroparesis.     

Acute and chronic effects of domperidone on gastric emptying in diabetic autonomic neuropathy

Gastric emptying was studied with a double radioisotopic method in 12 patients with insulin-dependent diabetes mellitus complicated by autonomic neuropathy and in 22 control subjects. In the diabetics, the acute and chronic effects of oral domperidone on gastric emptying, symptoms of gastroparesis, and glycemic control were assessed. Gastric emptying of solid and liquid was slower in diabetics than controls (P<0.001). Acute administration of domperidone increased the rate of both solid and liquid emptying (P<0.005). Domperidone was most effective in those patients with the greatest delay in gastric emptying. After chronic administration (35–51 days), domperidone had no significant effect on solid emptying (P>0.05), but was still effective in increasing liquid emptying (P<0.025). Symptoms of gastroparesis were less after domperidone (P<0.001).Dr. M. Horowitz was supported by a grant from the National Health and Medical Research Council of Australia.